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A ‘New Generation’ of Basin Planning

GEF/UNEP Floods and Droughts Management

By IW:LEARN

April 29^th, 2019

Changes in climate patterns are notably influencing the availability and quality of water resources across the world. This impacts our economies, our societies and the overall environment. With 20 per cent of the world’s population living in river basins that are likely to be affected by increased climate hazards by the 2080’s, it is critical that we strengthen our resilience and capacity to mitigate the impacts. Water resources are fundamental to the provision of drinking water, for industrial and agricultural use, and ensuring the evolution of our valuable ecosystems.

As water resources become scarcer, demand from competing sectors will continue to grow. This will drive changes in the way basins are managed in order to continue sustaining the different sectorsof the economy, society and environment. The ‘new generation’ of basin planning will need to consider the growing impacts caused by climate change.

Basin planning helps set appropriate objectives for the sustainable utilisation of the basin to ensure availability for current and future usages. This requires a more strategic and well-informed approach that engages across sectors. A good basin plan will enables a common vision for the basin among beneficiaries, and ensure the environmental considerations are not forgotten.

Basin Planning application in the Flood and Drought Portal. Credit: Flood and Drought Portal

The Flood and Drought Management Tools (FDMT) project, executed by DHI and the International Water Association (IWA), has developed the Flood and Drought Portal, which promotes methods on how to include floods and droughts considerations in planning. Water professionals need tools that include both the impact of interventions (i.e. investments) such as an irrigation scheme, water supply system, hydro power plant, etc., and external factors such as climate change or population growth.

Existing plans can be compared and new plans developed and evaluated. Existing plans are based on a baseline model depicting the current condition of the basin. New plans that incur alterations to the baseline model (i.e. the investments and external factors) are then evaluated using a Multi-Criteria Analysis (MCA) approach. The approach defines the strategy, which includes the concerns or priorities of different stakeholders and selects indicators on which the plans will be evaluated. The weights for each indicator are defined and an overall score is derived for each plan evaluating the impact of the new plan.

A Crop application has also been developed. The application can be used to inform alternations to the existing condition by indicating the increased water requirement for an irrigation scheme to grow a certain crop within the basin. The Crop application is adapted from the FAO Aquacrop model, assisting int eh selection of crops, and providing and estimate of the crop water requirmenet for a specific area of the basin. Specifically, the application has been adapted to enable stakeholders to use historical, and short- and long-term forecasted rainfall data (provided by the Data and Information application available in the Portal) for computation of crop yields.

For a basin where agriculture precedes other sectors in terms of water use, understanding the annual water requirement for irrigated agriculture to ensure adequate yields can better inform planning and management of water resources in the basin. Entering appropriate information in terms of the investments in new basin plans can ensure that decision makers base their decisions on better informed planning options. Information based on sound information can help ensure that the ‘new generation’ of basin planning scenarios are robust, resilient and pragmatic.